Electric ignition device for gaseous fuel



Sept' 4, 1955 H. W. RICE ET AL ELECTRIC IGNITION DEVICE FOR GASEOUS FUEL Filed April 7, 1955 2 Sheets-Sheet l INyENToRs Haf'oa W Hace and gyqzl'el L4. Dense. /M//M SePf- 4, 1956 H. w. RICE ETAL 2,761,947

ELECTRIC IGNITION DEVICE FOR GASEOUS FUEL.

Filed April 7, 1955 2 Sheets-Sheet 2 s um w @l INVENTORS Hapold WRce and Dana'e A erse.

HIS HTTORIVZ'Y United States Patent() ELECTRIC IGNI'IIONIILIVICE FOR GASEOUS F L Harold W. Rice and Daniel A. Derse, Los Angeles, Calif., assignors to Robertshaw-Fulton Controls Company, Greensburg, Pa., a corporation of Delaware Application April 7, 1955, Serial No. 499,902

8 Claims. (Cl. 219-32) serve a plurality of burners and be easily removed for 7 servicing or replacement.

1t is well known in the art that a circuit containing an electric resistance igniter cannot tolerate even slight changes in electrical resistance without also displaying variations in ignition performance. This characteristic has defeated the use of plug in igniters that are easily removable for servicing or replacement.

The present electrical connectors display definite varia- -tions of electrical resistance after repeated use and are not satisfactory for circuits of extremely low tolerances. Thus, their application to electric igniters has not been totally successful. y

Another restriction to the use of electric igniters is their inability to serve a plurality of burners adequately. If the direction or velocity of fuel ilow with respect to the igniter is varied, the ignition properties will also be subject to variation. Thus, it is necessary for successful operation with a plurality of burners, to provide a means whereby fuel from each burner is supplied to the igniter with the same angular relationship between the igniter and each fuel supply.

It is an object of this invention to incorporate in an electrical igniter a quick disconnect feature to permit easy replacement of the igniter.

Another object of this invention is to incorporate in an electrical igniter an improved plug in type connector that will undergo only minute variations of electrical resistance upon repeated use and during lengthy exposures to elevated temperatures.

Another object of this invention is to position a resistance coil that will serve a plurality of burners without varied ignition performance.

Another object of this invention is to incorporate in an electrical igniter, a plug-in type connector with selfcompensating prongs to maintain a constant contact pressure with a uctuating ambient temperature.

Another object of this invention is to incorporate in an electric igniter, a plug-in type connector with a springtype prong design that will maintain correct alignment and adequate electrical contact with its receptacle upon rotation of any individual prong with respect to its retainer.

In the preferred embodiment of this invention, an igniter coil is mounted in a chamber within a plug member which has a plurality of projecting prongs, each of said prongs being operatively connected to said igniter coil and adapted to be detachably received by a socket member for operatively connecting the plug member to the socket member.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a front elevation partly in section, of an ignition device embodying this invention;

Fig. 2 is a side elevation of the device shown in Fig. l;

Fig. 3 is a sectional View taken along the line III-III of Fig. 1;

Fig. 4 is an exploded perspective view of the ignition device;

Fig. 5 is an elevational view of a detail;

Fig. 6 is a front View of the detail shown in Fig. 5;

Fig. 7 is a side view of the detail shown in Fig. 5; and

Fig. 8 is a sectional view taken along the line VIII- V111 of Fig. 1.

Referring more particularly to the drawings, the electric igniter includes a socket member 10 and a plug member 12 which houses an igniting element later to be described. The socket member 10 is cylindrical in shape and of insulating material and provided with two parallel cylindrical conducting sleeves 14, 14 which are adapted to receive prongs 16, 16 ofthe plug member 12 to operatively connect the plug member 12 to the socket member 10.

The sleeves 14, 14 extend through holes spaced on a diameter of the socket member 10, and have flared portions 18, 18 at one end thereof to guide the prongs 16, 16 therein and to engage correspondingly ared portions at the end of the holes which tix the position of the sleeves 14, 14 with respect to the socket 10. Washers 22, 22 are attached to the opposite ends of the sleeves 14, 14 and engage the socket body 1t) to prevent movement of the sleeves 14, 14. The lugs 24, 24 projecting from the socket member 10 are attached to the sleeves 14, 14 in the vicinity of the washers 22, 22 and are provided with holes 26, 26 which enable the lugs 24, 24 to be connected to a source of electric power.

Two holes 28, 28 extending parallel to the sleeves 14, 14 and spaced on a diameter normal to that of the sleeves 14, 14 enable the socket member 10 to be attached by screws to a gas range. Each of the holes 28, 28 is countersunk to provide for seating of the screws below the face of the socket 1t).

The plug member 12 has a cylindrical body portion of insulating material and is provided with two spaced parallel conducting elements 32, 32 therein. Each end of the conducting elements 32 is enlarged to prevent movement of the conducting elements 32 with respect to the plug member 12.

The two prongs 16 have straight portions 34, 34 attached within the conducting elements 32 and portions 36, 36 projecting from the plug member 12 which are adapted to be detachably received by the conducting sleeves 14 as hereinbefore described. The projecting portions 36 are of sinusoidal configuration having four bight portions 38, 40, 42, 44 on each of the prongs 16, 16. The bight portions 38, 40, 42, 44 on each prong are disposed oppositely along a longitudinal axis established by a line constituting an extension of the straight portion 34. When the prongs 16 are inserted in the conducting sleeves 14 to operatively connect the plug mmeber 12 to the socket member 10, each of the bight portions 42 are deflected toward a line tangent to the bight portions 40, 44. This deflection causes a constant and positive spring force to insure electrical contact with the interior of the conducting sleeves 14. Since the prongs 16 are rectangular in cross section, two edges 45 on each bight portion 4i), 42, 44 engage the interior surface of the conducting sleeves 14 providing each of the prongs 16, 16 with six contact areas. The bight portions 38, 38 of the prongs 16, 16 are provided to absorb deiiections caused by misalignment of the prongs 16, 16 with respect to the conducting y sleeves 14, 14 eliminating the necessity for close dimensional tolerances.

Because of the six small contact edges on each prong 16, the electrical resistance of the connection will vary only minutely over a long period of use. It is to be noted that the rotation of any individual prong 16 with its conducting element 32 will not preclude correct alignment and adequate electrical contact with its receptacle and that the contact pressure will remain constant with a fluctuating ambient temperature due to the spring force created by the bight portion 42 deflecting toward a line target to the bight portions 40, 44,

A casing 46 surrounds the side portion of the plug member 12 but leaving the end portions thereof exposed. An annular element 43 is spaced from one end of the plug member 12 by four supporting elements 50, 50, 50, t) which are attached to the casing 45 at the end of the plug member 12 opposite the prongs i6, 16 to define a chamber S2 between the annular element 4S and the end of the plug member 12.

Two spaced conducting posts 54 having one end of each attached to the conducting elements 32 project into the chamber 52 and are positioned in a plane fixed by two opposite supporting elements 50, 50. An igniter coil S6 is connected to the ends of the posts 54 within the chamber 52 and in the plane established by the two opposite supporting elements 58, Si).

The electric igniter thus far described is designed to be positioned in a central part of a gas range having a plurality of burners. The chamber 52 is adapted to receive fuel through openings S8, 53, 58, S8 between adjacent supporting elements 5t), thus having four equally-spaced openings 58 for fuel. Fuel from a burner is directed to one of the openings 58 and normally to a plane established by the two adjacent supporting members and thus enters the chamber to strike the igniter coil. Since there are four equally-spaced supporting members 50, and the igniter coil 56 is in a plane established by two opposite supporting members, it can be seen that fuel entering the chamber S2 through the opening 58 between any two adjacent supporting members 5t) will strike the igniter coil 56 at a 45 angle.

The supporting elements 5t) are positioned to have their transverse axes along radii of the chamber 52 thus fuel directed normally to a plane established by two adjacent supporting elements 50 strikes each of the adjacent elements 50 at a 45 angle. The width of the supporting members Si) is substantial to cause slight converging of the fuel stream within the chamber 52. As a result, the fuel stream is narrower within the chamber 52 than outside.

In the operation of the igniter, the socket member 1G is attached to a gas range centrally of the burners and the plug member 12 is operatively connected thereto by inserting the prongs 16 into the conducting sleeves 14. The fuel lines from the burners to the igniter are arranged to direct fuel from each burner to the opening 58 between two adjacent supporting members 50 and normally to a plane established by the two adjacent supporting members 50.

When fuel is turned on at a burner, a fuel stream will ow into the chamber 52 through two adjacent supporting members 5@ converging slightly and striking the igniter coil at a 45 angle. lf another burner is turned on, fuel will enter the chamber 52 between two other adjacent supporting elements 541 to strike the igniter coil 56 at the same angle. Thus, it can be seen that the ignition properties of the igniter coil 56 remains the same for all burners. This is one of the important features of this invention.

Easy removal and replacement of the igniter coil is facilitated by the plug in connection between the plug member 12, and the socket member 1G. The plug member 1?. can be removed from the socket member 10 by a large number of times resulting in only minute variations in electrical resistance, and presenting another important feature of this invention.

Although a preferred embodiment of this invention has been shown and described herein, it is to be understood that the invention is not limited to the details of construction and arrangement of parts disclosed but is to be interpreted as claimed.

It is claimed and desired to secure by Letters Patent:

1. In an electric ignition device for a flowing fuel, the combination comprising a plug member having a plurality of spaced conducting elements therein, a casing carried by said plug member and defining a chamber therein, said casing having a plurality of supporting elements dciining equally spaced openings for permitting the flow of fuel into said chamber from a plurality of directions, said supporting elements being positioned radially of said chamber for directing the flow of fuel into said chamber, a resistance wire located in said chamber and operatively connected to at least two of said conducting elements, said resistance wire having its longitudinal axis in the same angular relationship with the plane of each of said openings, a plurality of prongs operatively connected to said conducting elements and projecting through a wall of said plug member, and a socket member having a plurality of conducting sleeves spaced therein, said sleeves being adapted for connection to a source of electric power and to detachably receive said projecting prongs to operatively connect said plug member to said socket member.

2. In an electric ignition device for a flowing fuel, the combination comprising a plug member having plurality of spaced conducting elements therein, a casing carried by said plug member, Said casing having an annular portion supported by a plurality of supporting members and defining a chamber therewithin and spaces between said supporting members to allow flow of fuel into said chamber, said supporting members being positioned radially of said chamber for directing said fuel ow, a resistance wire within said chamber and operatively connected to said conducting elements, said resistance wire having a longitudinal axis forming equal angles with the planes established by any two adjacent supporting members, a plurality of prongs operatively connected to said conducting elements and projecting through a wall of said plug member, and a socket member having a plurality of conducting sleeves spaced therein, said sleeves being adapted for connection to a source of electric power and to detachably receive said projecting prongs to operatively connect said plug member to said socket member.

3. ln an electric ignition device for a owing fuel, the combination comprising a plug member having a plurality of spaced conducting elements therein, a casing carried by said plug member, said casing having an annular portion supported by a plurality of spaced supporting members and defining a chamber therein, said supporting members each having its transverse axis extending radially of said chamber and having openings therebetween for cw of fuel between adjacent said supporting members and for converging said fuel ow into said chamber from a plurality of directions, a resistance wire within said chamber and operatively connected to said conducting elements, said resistance wire having its longitudinal axis in the same angular relationship with each of said directions, a plurality of prongs operatively connected to said conducting elements and projecting through a wall of said plug member, and a socket member having a plurality of conducting sleeves spaced therein, said sleeves being adapted for connection to a source of electric power and to dctachably receive said projecting prongs for operatively connecting said plug member to said socket member.

4. ln an electric ignition device for a tiowing fuel, the combination comprising a socket member having a plurality of spaced cylindrical conducting sleeves therein, said sleeves being adapted to be connected to a source of electric power, a plug member having a chamber therein, a plurality of conducting elements, cach of said conducting elements having a portion within said chamber adapted for connection to an electric circuit and a portion projecting through a wall of said plug member. said projecting portion being adapted to be detachably received by said conducting sleeves for operatively connecting said plug member to said socket member, said projecting portion being of generally rectangular cross-section and of sinusoidal configuration defining a plurality of bight por tions, said bight portions being adapted to flex radially toward the longitudinal axis of said projecting portion for establishing a bias for the edges of said bight portions upon the interior surfaces of said cylindrical conducting sleeves, at least one of said bight portions being adapted to align said plug member with said soci-:et member.

5. In an electric ignition device for a flowing fuel, the combination comprising a socket member having a plurality of spaced cylindrical conducting sleeves therein, said sleeves being adapted to be connected to a source of electric power, a plug member having a chamber therein and a plurality of conducting elements, each of said conducting elements having a portion within said chamber being adapted for connection to an electric circuit and a portion projecting through a Wall of said plug member, said projecting portion being adapted to be detachably received into said conducting sleeves for operatively connecting said plug member to said socket member, said projecting portion being of generally rectangular crosssection and of sinusoidal coniiguration defining a plurality of bight portions, each of said bight portions having a plurality of edges engageable with the interior surfaces of said cylindrical conducting sleeve for establishing electrical contact therewith.

6. In an electric ignition device for a flowing fuel, the combination comprising a socket member having a plurality of spaced cylindrical conducting sleeves therein, said sleeves being adapted to be connected to a source of electric power, a plug member having a plurality of spaced conducting elements therein, a casing enclosing said plug member and deiining a chamber therein, said chamber having a plurality of supporting elements dening equally spaced openings for admitting fuel from a plurality of directions, said supporting elements each having its transverse axis extending radially of said chamber for directing said fuel therein, a resistance wire in the central portion of said chamber and adapted to be operatively connected to at least two of said conducting elements, said resistance wire having a longitudinal axis having the same angular relationship with each of said openings, a plurality of prongs operatively connected to said conducting elements, said prongs having portions projecting through a wall of said plug member and adapted to be detachably received by said conducting sleeves for operatively connecting said plug member to said socket member, said projecting portions being of generally rectangular cross-section and of sinusoidal coniiguration defining a plurality of succeeding bight portions extending on opposite sides of the longitudinal axis of said projecting portions, said bight portions being adapted to move radially toward said axis upon engagement with the interior surfaces of said cylindrical conducting sleeves for establishing a bias for the edges of each of said bight portions upon the said interior surfaces of said sleeves.

7. An electric ignition device as dened in claim 6 wherein said supporting elements define a plurality of surfaces on the edges of said openings for converging the flow of fuel.

8. An electric ignition device as deiined in claim 6 wherein each of said bight portions have at least two points of contact with said interior surface of each of said sleeves for establishing electrical contact therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,094,051 Berg Apr. 21, 1914 1,898,418 Zwilling Feb. 21, 1933 2,049,560 Ezzo Aug. 4, 1936 2,385,699 Fox Sept. 25, 1945 2,495,206 Brus Jan. 24, 1950 2,530,827 Lakota et al. Nov. 21, 1950 

